The Key To Everything
by The Chuckinator
Summary: Some things happen by accident, and some things happen for a reason- like Sonic and Shadow were tied together, even before the ARK, but not by themselves... But by their families! Not only that, but they are all part of a protection program! So... Hiding from GUN is gonna work so well and will be easy... Right? A collab with Shadow7104. Proofread by TactileImp78.
1. Preperations

The Key To Everything

By Shadow7104 And The Chuckinator

Chapter 1: Preperations  


The sound of footsteps were in the strangely quiet castle as a figure in a black cloak raced down the empty hallways as voices echoed throughout the place.

"You! Stop!"

"You two go that way! Cut him off!"

"This is GUN! Stop unless you want to be arrested!"

The eyes of the cloaked figured widened as he paused there for a second, trying to decide where to go. Once realizing what the last male voice had yelled, his eyes hardened as a slight growl escaped his throat. The cloaked figure immediately returned his pace as he listened for clues about the whereabouts of the followers. He slipped through a large wooden door that could only be noticed if you knew how to look for it for that entire wall was wood. The excuse used is that the Royal family wanted to keep some details of what was originally on the ground before the castle was created, but in reality it was because of something that could destroy everything they know and love. Or that it could destroy an entire race… and maybe with a few adjustments... the entire planet.

But only if they had the key.

The cloaked figure leaned quietly against the door as he listened for the sound of retreating footsteps and yells toward the other side of the castle. A light relieved sigh left the figure's mouth as his attention turned away from the door and down into the hall. He walked slowly down the surprisingly long hallway as he looked around, for there were many other things in this hall too. For instance as he walked down the hallway, there was a statue for every royal that has helped protect this secret as it was "destroyed" right after it was created.

At least that's what they told the public- but somehow, now GUN had found out about it and are planning to use it on Doctor Eggman, unaware that it is,in fact, very unstable.

And that is why the weapon must remain hidden. Just as the key.

All four parts of it.

Soon, he had past all of the statues as he slowly walked up some stairs to a room filled with all kind of treasure- the "emergency" treasure, but the figure was unfazed for that. What he came for was in the middle of the room on a small pedestal. he slowly walked up to the machine, which was about the size of a handgun, and put the weapon under his cloak. He turned to the left and walked over to 9 tiles- equally length and size- and pressed into them as if it were a number pad on a keyboard.

"437253," he muttered under his breath as he pressed the specific tiles. When he let go of the last tile, a soft rumbling was heard as a small door opened as the gold and jewels that were on the ground on top of it were moved and a small staircase appeared leading out and the pedestal that held the weapon had disappeared into the floor. The figure smirked as he prepared to leave, but before he left, he held up his right wrist and took something off and quickly snapped it in two, giving off light yellow sparks, and tossed the two pieces into a nearby pile as he began to exit with the staircase. When it was clear that the cloaked figure was down, the doors closed and the pile of gold reappeared on top of the hidden door as a banging was heard. The sound of smashed doors was soon heard in the room as soldiers poured into the treasury room with guns high.

Sadly for them though, the figure and the weapon were already long gone. As the soldiers looked around for any clue of the weapon, a slight glimmer came off the two objects that did not go unnoticed by a certain GUN agent as she walked up to the two pieces and gasped as a familiar name was edge into the two sides.

 _Shadow the Hedgehog._

 _ **One Week Earlier**_

"Oh come on, Sonic!" Tails the Fox complained as his older brother ran around his Workshop, grabbing different things, putting them into a small backpack. "Why can't I ever go with you on these trips to your family?! I'm your little brother! I think it's time you introduce me to them, don't you think?!"

Sonic sighed. "I will, Tails, I will- but it'll have to be another time. I know you want to meet them -and I want you to also- but something came up and with how crazy my family's village is with it's entrances, Shadow's making me escort him in there for "official GUN business with the royal family."

"But you're just a commoner."

"Well, yeah, but Shadow just needs to get _in_ , the rest is whatever he needs to do. I'm not having any business with it." he said, as he folded over the top flap of the backpack and put it on his back, hanging on by his right shoulder. "Hey, I'll be back in two weeks, tops. With how much I like to take my runs, you should be ok for that little while I'm gone." He turned ready to head out the door and said. Amy will come over and visit every once in a while, and if something happens where you need me; you can always call my communicator and I'll be here in a jif." He gave a light smile as Tails returned one as he smiled.

"You're right."

"Yep, and I'll see ya in two weeks, lil' buddy." Then he was out the front door in a blur.

He stopped at Tails' bottom step and looked back at the Workshop as he sighed sadly.

"You told me yourself; you can't tell him about who your family really is for his safety." a new darker voice hit his ears.

"Yeah," he spat, "I did, but I _do_ hate lying to him, and this isn't helping!"

"Well," the voice responded as he stepped into the hedgehog's view. "The faster we get there, the faster you get back to him."

Sonic scoffed. "Whatever. Let's just go already, Shadow. It's already bad enough I have to get you in and then _I_ have to deal with _my_ family." He groaned. "This is gonna be a long two weeks."


	2. Meeting The Family

Chapter 2: Meeting The Family

The two hedgehogs got in Shadow's car as Sonic sat in the passenger seat. He sighed and thought about his family.

"It's been so long since I've seen them," he said, looking at Shadow as the black hedgehog drove. "Do you think they'll be happy to see me?"

"They're your family, Sonic," Shadow said. "Of course they'll be happy to see you."

Sonic nodded and pulled out the letter his mother had sent him a week ago. He sighed and began to read.

 _Dear Sonic,_

 _It is with a heavy heart that I send this. Your father has recently passed away, and the Royal Family is in need of a new king. We would like you to come to the funeral, and, if possible, your coronation. Since you are next in line for the throne, this is very important business. I would also like to talk to you about something that we have guarded for centuries. Our kingdom has stood for a long time, and I believe it is time for you to know the truth. Please come at once._

 _Your mother,_

 _Queen Aleena._

The blue hedgehog sighed and put the letter away. "My father...I wish I could have been there for him. If I had known that he was dying..."

"It's not your fault, Sonic," Shadow said. "Everyone dies. It's a part of life."

Sonic crossed his arms and looked out the window as they drove out onto the freeway. He watched as Station Square faded into the distance and thought about Tails. The fox was his best friend, but he had to lie about his family and heritage. It hurt him that he had to do so.

"I don't like lying to Tails," he said. "He'll find out sooner or later, and if he finds out that I've lied to him, he'll be mad for me not trusting him."

Shadow said nothing for a few minutes, keeping his eyes on the road. Finally, he spoke. "It's for the best, Sonic. Not everyone has to know you're royalty. Knuckles and I are the only ones who know."

"That's because I trust you with my secret," Sonic said. "Knuckles has known for ages. We met him when we were kids, and he knew my mom."

"Well, if you really want to tell Tails, then I suggest you tell him when you're ready."

Sonic nodded. A few minutes later, he yawned and fell asleep. As Shadow drove, the landscape changed, with the cities disappearing. Soon, they were in the countryside; night had fallen as well, and they were almost to their destination. It wouldn't be long before they reached the castle. Shadow tapped Sonic on the shoulder, who woke and yawned.

"Are we there yet?" He asked, yawning.

"Almost," Shadow said.

Sonic smiled and put an arm over Shadow's shoulder. before long, Shadow pulled off of the freeway and headed down a street. A large castle could be seen in the distance, surrounded by a large wall. It overlooked a town, and Sonic looked around.

"Here we are," he said. "Mobotropolis."

Shadow nodded. He parked the car outside of the castle, and the two got out. Sonic looked at it and sighed.

"You ready?" Shadow asked him.

Sonic hesitated, but nodded. "As ready as I'll ever be. Come on; let's go."

He ran off as Shadow followed him. When they reached the castle gates, a guard looked at them.

"Prince Sonic, we have been expecting you," he said, opening the gates. "Please, come in."

The blue hedgehog smiled and walked inside, followed by Shadow. The guard escorted them up to the castle and knocked on the door. A few minutes later, it opened to reveal a female hedgehog. She was five feet tall with purple fur, and wore a white dress. She smiled when she saw them.

"Sonic, welcome home," she said, and looked at Shadow. "You must be Shadow. I am Queen Aleena."

"It's an honor to meet you," Shadow said, bowing.

The queen smiled and led them inside. "Manic, Sonia, your brother's here!"

There was running, and two hedgehogs, one female and one male, came downstairs. They smiled when they saw Sonic. The blue hedgehog looked at them and gulped.

"Hey, guys," he said. "I'm back."


	3. Family Reunion

Chapter 3: Family Reunion  


The sounds of running footsteps were heard from the side rooms, echoing into the throne room as two familiar people entered the room, surprising Sonic that they had barely changed their appearance, Sonia's hair now slightly longer than he remembered from 5 years ago. He stood quietly as his siblings stared at him, clearly deciding if it's him-especially since his eyes are green now.

"Hey, sibs." He said after a bit, trying to break the uneasy silence. Shadow stood quietly as Sonia walked up to the blue hedgehog as she smiled-

-then slapped him in the face hard.

"That," she said calmly as Sonic held his face from the pain, "was for leaving without saying 'goodbye.'" Shadow quietly chuckled at the scene as the two siblings chuckled themselves. "It is good to see you again." She commented as Sonic smiled warmly as she gave him a hug.

"You too."

Not wanting to be left out, Manic jumped in on the hug- Shadow smirked at the three. Clearly they all had different ways of life, but you could tell that they still were close.

The hug lasted a few minutes more until the pink hedgehog broke off saying. "It's been five years. I want to know what you've been up to."

Sonic sighed, then chuckled. "I've been through a lot, that's for sure."

"Then let's go to the den and sit down- a.k.a you're still telling us what you've been doing."

Sonic slumped. "Fine."

"Yes, while you kids do that I need to have a talk with Mr. Shadow here about what GUN needs." Queen Aleena said to her children as she turned to Shadow. "Follow me please."

The two walked down the corridors in the West Wing- the Queen chose this area for no one had been in it since she was a little girl because her parents forbid it- and when she was old enough she was finally told why; to make it forgotten so no one will ever go inside for the objects hidden throughout the wing. For this wing is where dangerous items have been hidden...

... All except one.

"I assume you weren't sent here just to 'check up' on our kingdom." She stated as she walked slightly ahead of the black hedgehog who was eying his surroundings. "And, from the looks of it, you know where we are." Her face was serious, no other emotion showing.

Shadow nodded, not needing to say it. "Then you know what I'm here to look for."

She sighed as she continued walking, passing some metal guard statues. "Yes, I do." She glanced towards the black hedgehog then back to the corridor as she sighed. "But, as you should know, it's not here- it was destroyed."

Shadow nodded at the Queen's comment. "Yes, that is what the records say, but considering what we have on family from your family, the Commander assigned me to check up on the situation." He said, clearly not letting down on his mission.

The Queen stopped and sighed, "Of course." She glanced at the wall. "G.U.N has to know of our hidden treasury by now, that's where it would be if it exists." She said, emphasizing her words. She turned to the black hedgehog. "You are welcome to look around.. and see if Sonic would want to help you- poor thing is probably being driven crazy right now."

And with that, the Queen left leaving the black hedgehog alone to start his search.


	4. Shadow's Mission

Chapter 4: Shadow's Mission

As Shadow looked through the castle, Sonic, Manic and Sonia went to their room. Manic sat on his bed and looked at his brother, who was sitting on his own. He looked around and sighed.

"I missed this place," he said. "But I'm glad I'm back."

"Did you get Mom's letter?" Sonia asked.

Sonic nodded. "Yeah...that was the reason I came back. I can't believe that Dad's dead!"

"It was a shock, I admit," Manic said. "But he was ill...it was his time."

"And apparently I'm going to be the next king...when's my coronation?"

"A few days after the funeral, which is a week from now."

"Enough about that," Sonia said, looking at Sonic. "How have you been, brother?"

"I've been good," Sonic said. "Been living in Station Square since I left. I've become a hero there."

"So we've heard. Robotnik's still been causing trouble?"

"Yeah. He calls himself Eggman now. My friends and I have been foiling his plans every time."

"You have new friends?"

Sonic nodded, smiling. "They're great friends. My best friend is Miles Prower, but he calls himself Tails. He's a great person; an amazing inventor and pilot. He has two tails also, so he can fly with those. Another good friend of mine is Shadow; he's the person you saw with me. Shadow works for GUN, a government agency. There's also Silver, Chaotix, Babylon Rouges, and others I've made friends with."

"It's always good to make new friends," Manic said, and then sighed. "Sonia and I don't really have any; we've basically been cooped up here at the castle." He looked at Sonic. "Why'd you leave, anyway?"

"I...I just couldn't take all the responsibility. I wanted to do something new; travel the world and have more adventures. So...I left. I'm sorry I did without telling you."

"What adventures have you been on?"

Sonic thought about it. "Well...mostly ones trying to defeat Eggman. Fighting Perfect Chaos, the ARK incident...there was also one where Eggman broke Earth apart and released a deity called Dark Gaia. He turned me into a werewolf in the process..."

"You're a werewolf?" Sonia asked, shocked.

"Yeah, I am. It used to happen every night, but now it only happens on the full moon."

"When's the next full moon?"

"I think sometime this week," Sonic said. "I'll transform then."

"Do you have any control in wolf form?" Manic asked his brother.

"Yeah, I do."

"That's good," Sonia said.

The blue hedgehog nodded, and looked at his sister. "So...mom also mentioned that she wanted to tell us something...do you know what it is?"

"No, I don't. You?"

"No clue. What about you, Manic?" The green hedgehog shook his head, and Sonic shrugged. "Oh well. She'll tell us later. Hey, where's Shadow?"

"Mom wanted to talk to him about something," Manic said. "Shall we go look for him?"

Sonic nodded and stood up, walking out of the room. His siblings followed him and looked around, hoping to find Shadow.

* * *

The black hedgehog was looking around as well, walking further down the corridor that Aleena had left him in. He had to find whatever it was that the Queen had told him about...the Commander wanted it very badly. Shadow had heard legends of something in the castle that was extremely powerful, but didn't know what it was. The only thing that he knew was that it was protected behind some sort of door, and he had to find it.

He saw torches ahead, and walked down the hall cautiously. The corridor forked into two, causing Shadow to wonder which way to go. A few minutes later, he heard voices. Shadow leaned up against the wall and peered down the hall. Three shadows appeared, and Shadow relaxed. It was only Sonic, Sonia and Manic. He smiled and ran up to them.

"Hey," he said. "What are you three doing down here?"

"We've been looking for you," Sonic told him. "Sonia, Manic and I stumbled into this corridor; we've never seen it before, so we decided to investigate. What about you?"

Shadow sighed. "I...suppose I could tell you. I'm on a mission for GUN, looking for something hidden in this castle. It's behind some sort of door, and I haven't been able to find it."

"We can help," Sonia said, smiling

"I'd appreciate that. Thanks."

The pink hedgehog nodded, and the four walked down the hall. Unbeknownst to them, Queen Aleena was hidden in the shadows, watching them. A smirk came to her face.

"It is time," she said to herself. "My family has begun their search, setting events into motion. The Key must be found."

She vanished in a flash of light.


	5. The Door

Chapter 5: The Door  


"So, you've never been down this hall?" Shadow asked the triplets as they continued down the hallway.

"No," Sonic responded, looking at everything they passed. "Though it looks like this place has been long abandoned." He nodded to the walls and the others looked at the worn and deteriorating wallpaper. Manic walked up to the wall and ran his hand along it.

"Manic!" Sonia scolded and the green hedgehog rolled his eyes.

"Relax sis. I was just feeling to see about how long it's been untouched. It definitely has been long enough though that the walls haven't collapsed." He said as he waved his right arm toward the wall; hitting the wall. "Ow!" He whined for a second as he jumped away from the wall and then looked back to the cracking forest green wallpaper, resulting in his siblings and Shadow to look at him funny.

"Manic?" Sonic questioned, "What is it?"

Manic only responded by running back to the wall and placing an ear to it; his hand tapping different parts. His two siblings looked at each other both thinking their brother had gone crazy. Shadow only watched the green hedgehog as he lifted his ear off the wall and looked at them.

"It's hollow."

"What?" Sonia gasped as Shadow looked at the three. "Is this possible?"

Sonic blinked repeatedly in shock. "Obviously." He mumbled.

Shadow approached the wall, feeling for the range of the hollowness. "I think...this is a door."

"What?!" The three gasped.

"That's not possible." Sonia shook her head as Manic and Sonic helped Shadow try to figure out the door and how to open it.

Sonic grunted. "Sonia, help!"

She blink then ran over to help the three. Unknown to the four, four colors began to glow through the paper- red, blue, green, and pink. Sonic was the first one to notice and yelled, "Guys, back! Now!"

The three didn't argue and watched as the sound of gears were heard and the wall open in half, revealing a metallic door which slid open, the doors disappearing into the floor. The four hedgehogs watched in astonishment, then the floor beneath them rose quickly as a slide formed into the door. The four couldn't react as they slid into the opening; the door and all hints of it disappeared once the four passed the entrance.


	6. A Journal Of Secrets

Chapter 6: A Journal Of Secrets

Everyone screamed as they fell down a tunnel. The tunnel opened and they fell into a large room. Sonic groaned and sat up, rubbing his back as he looked around. Manic, Sonia and Shadow had also sat up.

"Where are we?" Sonic asked.

"I...I'm not sure," Manic said as he stood. "Sonia, do you have any ideas?"

Sonia shook her head. "Not really," she replied.

"It seems we're in a hidden room," Shadow said as he got up and looked around. He smirked, "This may be what I've been looking for..."

Sonic smirked and started walking around. The room was pretty big, filled with books, artifacts, and other things. The four hedgehogs started to look around, and saw some medallions on a table. Sonia walked up to them.

"These look like the medallions that we used to have," she told Sonic.

"They do," Sonic agreed. "But these are different. They each have some sort of animal engraved upon them. The blue one has a dragon, green has a tiger, pink has an eagle, and black has a centaur. Each medallion has the same color as our fur."

"Interesting," Shadow said. He reached out to touch the black medallion, and it started to glow. It sent out a bright light that shocked him, and he groaned. The other medallions shocked the others as well. When the light faded, the medallions had engraved themselves on the chests of Sonic, Manic, Sonia and Shadow.

"What...what was that about?" Manic asked as he looked at the engraving on his chest.

"I'm not sure, Manic," Sonic said. He looked at his also.

Sonia shrugged and walked away, looking at the books. As she rummaged through them, she saw a diary. Her eyes widened as she saw the name on its cover.

"Manic, Sonic," she said, holding up the diary. "This diary was written by our mother!"

Sonic and Manic rushed over as Sonia opened it. Shadow walked up to the group also, curious about what the diary had to say. Sonia turned to the first entry and began to read.

 _June 21, 1952._

 _My parents have finally completed it. After working with scientist Gerald Robotnik, they have achieved what they have been working on for so long. The Key is finally complete. It will unlock a weapon that we have been creating. In order to activate it, the Key must be used._

 _June 30, 1952._

 _Gerald has been working on a project for us in the ARK. Medallions have been created that will allow the wearer special transformation powers, passed down through generations. My family will use them when the time is right._

Manic's eyes widened at that, and he looked at the engraving on his chest. "So these will allow us to turn into animals. Cool!"

"Most likely the ones engraved on them," Sonic said. "Let me read."

He took the diary and flipped a few pages over, then saw another entry.

 _August 12, 1954._

 _The weapon is almost ready. With the right amount of Chaos Energy, along with ancient technology used to create it, it will have power unimaginable. It must not fall into the wrong hands. There are already enemies searching for it._

"Why would the Royal Family make a weapon like that?" Shadow asked.

Sonia, Sonic and Manic all shrugged. Manic took the diary, flipping to the next entry. This one was by Gerald Robotnik.

 _December 4th, 1954._

 _After many long years, the weapon is finally complete. GUN has gotten wind of it and is searching for it as we speak. Aleena's parents have passed away, and she has given birth to a black hedgehog named Shadow. We have decided to inject him with blood from an alien named Black Doom, creating the Ultimate Life Form. He will have many powers when he grows older._

Shadow's head snapped up, and he grabbed the book. The black hedgehog flipped to the back of the book, reading the last entry.

 _January 1st, 1955_

 _GUN has found the ARK and is invading it. No doubt they want the weapon, along with Shadow. Because of the Chaos Energy in Aleena's and Shadow's bodies, both people are immortal. His mother, Aleena, decided to wipe his memory of her to keep him safe, and ejected him down to Earth in a pod that will put him into suspended animation. I can only hope that he will awaken one day, remember who he is, and join his mother once again. The weapon has been hidden, and the Key was split into four parts, hidden as well._

The journal entry ended, and Shadow set the book down. Disbelief was on his face, and he looked at the royal hedgehogs, who were also shocked.

"I'm your...brother," he told them.


End file.
